• Skip to main content
  • Skip to search
  • Skip to footer
Cadence Home
  • This search text may be transcribed, used, stored, or accessed by our third-party service providers per our Cookie Policy and Privacy Policy.

  1. Community Forums
  2. Custom IC SKILL
  3. How to create Coaxial shielded path

Stats

  • Locked Locked
  • Replies 4
  • Subscribers 144
  • Views 15304
  • Members are here 0
This discussion has been locked.
You can no longer post new replies to this discussion. If you have a question you can start a new discussion

How to create Coaxial shielded path

infy
infy over 16 years ago

 

 Hi ,

I just used used your techinque to generate a single layer shield path.It is working fine.But I also want to go for coaxial shielding for metal2 onward . I want the code such that depending on selected layer ,it should overlap the shield path with higher metal layer with concerned vias, and similarly with bottom metal layer.So can you help me how to proceed .

Regards,

Infy

  • Cancel
  • Austin CAD Guy
    Austin CAD Guy over 16 years ago

     The same rodCreatePath command is used with all the sub parts. The side metal is two offsetSubPath, the top and bottom metal are encSubPath and the vias are subRect.The Virtuoso Relative Object Design User Guide has a good description on using these optional arguments. The descriptions there are much more than can be put into this forum.

    I usually start by designing it interactively and then saving the template. This gives me something I can use to copy into my SKILL.

     Ted

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
  • infy
    infy over 16 years ago

     Thanks Ted.I have tried that option , but I am trying to write a code, to automatically selct the bottom layer and top layer and the corresponding vias concerned ,if we just selected the layer to draw the signal.Since I used the CCSslotMetal.il as a reference ,to pass the layer as a variable, iam pondering if we can use some flow control operation to do the job. By using layer variable, if we can perform some boolean operation  to select higher level of metal and lower layer of metal and vias accordingly ,then I hope we can reach our goal.Can you help in me this regard.

    Thanks

    Infy

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
  • Austin CAD Guy
    Austin CAD Guy over 16 years ago

     You need to create a data structure which maps the routing layer to the top, bottom and via layers. This can be a table keyed on the drawing layer. The table value could be a disembodied property list which has the slots of topLayer, bottomLayer, topVia , bottomVia and the design rules or get the design rules from the techfile. 

    sheildTable = makeTable( "layers" nil)
    sheildTable["metal2"] = list( nil topLayer "metal3" topVia "via23" topRules list(.2 .2 .3 .01 .01) bottomLayer "metal1" bottomVia "via12" ....)

    The table is keyed by the current layer, the value is then parsed to get the layers associated and the rules and then passed to the rodCreatePath.  This information can be stored in the controls section of the techfile if necessary.

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel
  • infy
    infy over 16 years ago

     Thanks man.

    Regards,

    Infy

    • Cancel
    • Vote Up 0 Vote Down
    • Cancel

Community Guidelines

The Cadence Design Communities support Cadence users and technologists interacting to exchange ideas, news, technical information, and best practices to solve problems and get the most from Cadence technology. The community is open to everyone, and to provide the most value, we require participants to follow our Community Guidelines that facilitate a quality exchange of ideas and information. By accessing, contributing, using or downloading any materials from the site, you agree to be bound by the full Community Guidelines.

© 2025 Cadence Design Systems, Inc. All Rights Reserved.

  • Terms of Use
  • Privacy
  • Cookie Policy
  • US Trademarks
  • Do Not Sell or Share My Personal Information